Means for detecting the opening of sealed envelopes



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Patented Sept.`6, 1892'.

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UNITED STATES PATENT OFFICE.

LONIE P. CALLMEYER, AOF MADISON, NEV JERSEY.

MEANS FOR DETECTING THE OPENING OF SEALED ENVELOPES.

SPECIFICATION forming part of Letters PatentNo. 482,073, dated September6, 1892.

Application ined July 25, lsel.

.To all whom it may concern:

Be it known that I, LONIE P. CALLMEYER, a citizen of the United Statesof America, residing at Madison, county of Morris, State of New Jersey,have invented and made a new and useful invention in means for detectingwhen an envelope, after having been once sealed, has been unlawfullyopened intransit from the sender of the same to the one to whom it isdirected, of which the following is a specification.

It is well known that in order to open an envelope which has been sealedwith gum, Without detection, it is only necessary to soften the gum bymoisture. This is usually done by steaming, and after such an operationthe envelope is readily resealed so that the fact that it has beenopened cannot be known with certainty.

The object of my invention is to prevent any person from unsealing anenvelope' by moisture Without the fact being apparent; and to this endit consists in the means herein specified and claimed.

In order that persons skilled in the art may understand, construct, anduse myinvention, I will proceed to describe it, referring to thedrawings, in which- Figure l is a representation of my invention asapplied to an envelope previous to sealing. Fig. 2 is the same, showingthe appearance of the envelope after the same has been opened bysoftening the gum by moisture.

A is the envelope proper.-

Bis the flap to which gum is usually applied.

O is the part of the envelope to which the flap B is sealed.

D isa spot of ink, composition, or substance applied to the under sideof the flap of the envelope, so that when sealed itis between the ap Band the part C, and concealed from view.

E represents the gum under the iiap B.

Serial No. 400,711- (No model.)

envelope is im material.` Ido not confine myp self to any particulardesign nor to the particular composition of ink.

To illustrate how my invention is to be perf formed, I will describe theoperation. Before the envelope is closed by sealing, ink or compositionof the nature hereinbefore described is placed or printed in any mannerupon the under side of the flap or on the part C of the envelope, sothat when sealed it will lie between said two surfaces. The envelopewith its contents are now ready for mailing. Should any one attempt toopen the envelope unlawfully by moisture, lthe said ink compositionwhich is between the gummed surfaces will immediately run or spreadovel1 and into the paper, so that when resealed and again opened by thelegitimate or rightful receiver of the envelope it will be readily seenthat it has been previously opened and investigation may be demanded.The importance of this or other means of detection will beapparent tothose who have suffered for the want of it.

I-Iaving now fully described my invention and the manner in which I haveembodied it, what I claim as my invention, and desire to secure byLetters Patent, is-

` The herein-described envelope having soluble or fugitive ink appliedto its inner surface and adapted to be covered and inclosed by a flap,substantially as described, said soluble or fugitive ink being slightlyremoved from the line of gum for securing the Hap, Substantially asdescribed.

LoNIE P. oALLuEYER. Witnesses:

VIRGINIE CALLMEYER, AMos C. RATHBUN.

